apache proxy path prefix 404 slugs issue

Hi,

I have an apache web server with vhost for mysite.com with ProxyPass/ProxyPassReverse like:

    ProxyPass /h/ https://wp.mysite.com:83/ retry=0
    ProxyPassReverse /h/ https://wp.mysite.com:83/ retry=0

wp.mysite.com is served by another apache server and has a vhost like this:

<VirtualHost *:83>
    ServerName wp.mysite.com 

    DocumentRoot /opt/wordpress
    ErrorLog /var/log/httpd/wp.mysite.com.error.log

    <Directory "/opt/wordpress">
        Options Indexes FollowSymLinks
    
        AllowOverride None
    
        Require all granted
    </Directory>

    SSLEngine On
    SSLProtocol all -SSLv2 -SSLv3
    SSLCertificateFile /etc/ssl/certs/mycert.crt
    SSLCertificateKeyFile /etc/ssl/certs/mycert.key
    SSLCertificateChainFile /etc/ssl/certs/myCA.crt
</VirtualHost>

This works for https://mysite.com/h/ and other pages such as /wp-admin/, /wp-content/ (so the images, css, js etc…) but posts/pages are giving a 404.

Like: https://mysite.com/h/my-page

The access_log for the wp.mysite.com web server (the one serving wordpress) has:

"GET /my-page HTTP/1.1" 404 254 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0"

So without the /h

WP_HOME and WP_SITEURL are set to https://mysite.com/h

Any idea what I can do to make this works?

Thanks